Currently, most of the mobile devices, e.g., mobile phones and flat-panel computers, are equipped with a camera assembly, so as to achieve the conversion between an optical signal and an electric signal, and record and store image information, thereby to shoot a picture or a video. However, it is impossible to completely seal the camera assembly and a rotor of a motor in the camera assembly may drive a lens to move up and down, so micron-sized dust may enter the imaging region of the camera assembly through the gap between the rotor and the housing of the motor. At this time, the camera assembly may be contaminated, so that more than a half of all defects for the camera assembly are caused. Hence, the yield of the camera assemblies and the mobile devices may be adversely affected.
There are principally the following two schemes for preventing the contaminations. In the first scheme, it is necessary to add as many dustproof structures as possible during the designing of the camera assembly, e.g., a dustproof groove is added inside the motor of the camera. At this time, the size of the motor may increase due to the dustproof groove, so it is adverse to the miniaturization of the mobile device. In the second scheme, it is necessary to ensure as high dustproof level of the environment where production lines for the camera assembly and the mobile devices are located as possible, e.g., in the factory for the camera assembly, the dustproof level of the environment where the camera assembly is assembled is 100, and a dustproof level of some topical regions is 10.